DE 195 28 762 C1 discloses a ram that has a rectangular cross section, the thickness of which essentially corresponds to the individual force-fitting surfaces of the vertically packed staples that are generally referred to as holding elements or anchors. The ram severs the anchors from a metal strip that extends perpendicular to the longitudinal axis A of the ram. The longitudinal axis of the ram extends parallel to the center lines of the bores in the toothbrush head, i.e., when a borehole is stuffed with a bristle cluster, its center axis is aligned with the longitudinal axis of the ram. The pressing surface of the ram is referred to as the end face. The ram has wider longitudinal sides and narrower face sides that form a rectangle and the cross section of which essentially corresponds to the cross section of the holding elements.
A bristle cluster extends perpendicular to the longitudinal axis of the ram, wherein this bristle cluster is subsequently pressed into a borehole and deformed into the shape of a U while being pressed into the borehole. The lateral edges of the holding element actually cut into the edge of the borehole in the brush head during this process. The ram presses the holding element into the edge material of a borehole in the brush head until the anchor no longer protrudes from the surface of the brush head. The slot produced in the borehole wall by the anchor while it is pressed into the borehole presses against the edges of the longitudinal sides of the anchor with such intensity that the anchor is rigidly fixed in the brush head and the bristle cluster is immovably anchored in the borehole.
EP 1 088 495 A also discloses a stuffing tool ram that is used for driving a strip-shaped holding element into a borehole that accommodates a bristle cluster. A thin metal wire extending perpendicular to the ram is inserted into the stuffing tool. The free end of the wire perpendicularly protrudes into the channel guiding the ram. When the ram is displaced in the direction of the toothbrush, it shears off a section of wire that is then transported in the direction of the toothbrush head along the channel and ultimately forms the holding element. During the displacement of the ram, the holding element collects a bristle cluster consisting of numerous filaments, wherein the holding element centrally deforms the bristle cluster into the shape of a U. The bristle cluster is then pressed into a borehole in the toothbrush together with the anchor in this fashion. The holding element is pressed into the borehole until it is no longer accessible from outside and the free end of the bristle cluster protrudes from the borehole by a predetermined distance. The end face regions of the holding element carve into the wall of the borehole such that grooves are formed. Due to the elastic material of the brush head, these grooves firmly press against the lateral faces of the holding element and thusly hold the holding element in the borehole. The bristle cluster can be reliably anchored in the borehole in this fashion.
In modern toothbrushes, the bores frequently are no longer aligned with the longitudinal axis of the ram, i.e., the bores are inclined relative to this longitudinal axis such that the bristle clusters do not perpendicularly protrude from the surface of the toothbrush head, but rather with a certain incline. Practical experience showed, however, that this frequently leads to damages to the pressing surfaces or to the end of the ram breaking off. This is associated with significant installation and repair expenditures because the ram needs to be removed from the stuffing tool, trimmed and contoured anew. In addition, this also leads to significant production losses because no toothbrush heads can be stuffed during these repair procedures.
Consequently, it is desirable to provide a ram with a service life that is not only extended when it is used in connection with bores that are aligned with the longitudinal axis of the ram, but also bores that are inclined relative to the longitudinal axis of the ram, wherein this ram is also not subject to a premature fractures or other damages. It is also desirable that the holding elements or anchors can be neatly and precisely pressed into the boreholes in order to reliably hold the bristle clusters in the boreholes.